In general, compressors convert electrical energy into kinetic energy and compress gas by the kinetic energy. The compressors include a rotary compressor, a scroll compressor, a reciprocal compressor and the like according to a compression mechanism.
FIG. 1 is a sectional view showing an exemplary reciprocal compressor. As shown in FIG. 1, a reciprocal compressor includes a casing 10, a driving motor M positioned within the casing 10 to generate a rotation force, an elastic supporting unit 20 to elastically support the driving motor M to the casing 10, a frame F having a cylinder 30 and positioned at an upper portion of the driving motor M, a crankshaft 50 penetratingly inserted in the center of the frame F and fixedly coupled to a rotor 41 of the driving motor M, a piston 60 movably inserted in the cylinder 30, a connecting rod 70 used to connect the crankshaft 50 to the cylinder 30 to thus convert the rotational motion into a linear reciprocating motion, thereby transferring the linear reciprocating motion to the cylinder 30, a valve assembly VA mounted at one side of the cylinder 30, and a suction muffler 80 and a discharge muffler 90 connected to the valve assembly VA.
The casing 10 is connected to a gas suction pipe 1 into which gas is introduced and a gas discharge pipe 2 through which a compressed gas is discharged.
Reference numeral 3 denotes a loop pipe, 42 denotes a stator, and SI denotes a silencer.
An operation of the reciprocal compressor will now be explained.
First, upon applying power to the compressor, the driving motor M is driven to generate a rotation force. The rotation force of the driving motor M is then delivered to the crankshaft 50 to rotate it. The rotational motion of the crankshaft 50 is converted into the linear reciprocating motion by the connecting rod 70 coupled to an eccentric portion 51 of the crankshaft 50. The linear reciprocating motion is transferred to the piston 60 to linearly reciprocate the piston 60 within the cylinder 30. The linear reciprocating motion of the piston within the cylinder 30 and an operation of the valve assembly VA suck gas into the cylinder 30 via the gas suction pipe 1 and a suction muffler 80, and then the sucked gas is compressed therein to thus be discharged. The discharged compressed gas is discharged outside the casing 10 through the gas discharge pipe 2.
In the compressor, on the other side, the connecting rod 70 which converts the rotational motion of the crankshaft 50 into a linear motion to transfer it to the piston 60, as shown in FIG. 2, includes a rod portion 71 having a certain length, an annular large end portion 73 extending from one side of the rod portion 71 and having a through hole 72 therein, and an annular small end portion 75 extending from the other side of the rod portion 71 and having a through hole 74 therein.
Regarding the connecting rod 70, the eccentric portion 51 of the crankshaft 50 is inserted into the through hole 72 of the large end portion 73, and a piston pin 100 which connects the piston 60 to the connecting rod 70 is inserted into the through hole 74. of the small end portion 75.
In the arrangement shown in FIGS. 1 and 2, the connecting rod 70 is integrally formed and as a result it is very complicated to perform an assembly operation for respectively coupling the connecting rod 70 to the eccentric portion 51 of the crankshaft 50 and to the piston 60. Particularly, in the case that the cylinder 50 is integrally formed with the frame F, the assembling operation for respectively coupling the integral connecting rod 70 to the eccentric portion 51 of the crankshaft 50 and to the piston 60 can hardly be performed.
In order to solve such problem, one approach has been developed such that the connecting rod 70 is divided into two separate components, and each divided component is coupled to the eccentric portion 51 of the crankshaft 50 and to the piston 60, to thereby connect the component coupled to the crankshaft 50 and the component coupled to the piston 60 to each other.
The technology disclosed in JP10196537 describes such an approach with an exemplary detachable connecting rod, as shown in FIG. 3. The detachable exemplary detachable connecting rod includes a large end portion block 210, a rod integral-type small end portion member 220 coupled to the large end portion block 210, and a coupling pin 230 to connect the large end portion block 210 and the rod integral-type small end portion member 220 to each other.
The large end portion block 210 is composed of a body 212 having a particular shape and a certain thickness and also having a through hole 211 therein. An insertion groove 213 formed in a side portion of the body 212 to have a certain inside diameter and depth, and a pin hole 214 longitudinally penetrates the insertion groove 213.
The rod integral-type small end portion member 220 is composed of a filled cylindrical rod portion 221 having a certain length, and an annular small end portion 223 extending from one side of the rod portion 221 and also having a through hole 222 therein. A pin hole 224 is penetratingly formed at an end part of the other side of the rod portion 221.
Regarding the detachable connecting rod, as shown in FIG. 4, the large end portion block 210 is inserted onto the eccentric portion 51 of the crankshaft 50. The rod integral-type small end portion member 220 is coupled to the piston 60. The rod integral-type small end portion member 220 is then inserted through the cylinder 30 to allow the rod portion 221 of the rod integral-type small end portion member 220 to be inserted into the insertion groove 213 of the large end portion block 210. Thereafter, the pin hole 214 of the large end portion block 210 is aligned to the pin hole 224 of the rod portion 221 of the rod integral-type small end portion member 220, and then the coupling pin 230 is inserted into the pin holes 214 and 224.